Cooling system for rackmounted electronic equipment having independent evaporator and condenser airflows

ABSTRACT

A closed loop cooling system for electronic equipment. The system includes a cabinet having a top panel, walls, and a door defining an enclosure. A rack is within the enclosure, and the electronic equipment is mounted thereto. An evaporator is within the enclosure below the electronic equipment. Recirculated cabinet airflow warmed by the electronic equipment is directed to the evaporator, cooled by the evaporator, and directed back to the electronic equipment to cool the electronic equipment. A condenser is in fluid communication with the evaporator to circulate coolant therebetween. Ambient airflow from outside the cabinet flows across the condenser to cool coolant flowing therethrough. The recirculated cabinet airflow is maintained independent of the ambient airflow, thereby preventing introduction of added heat or contaminates into the recirculated cabinet airflow, and not affecting air pressure of the ambient airflow.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/465,193 filed on Mar. 21, 2017, which claims the benefit ofU.S. Provisional Application No. 62/312,942 filed Mar. 24, 2016. Theentire disclosures of these applications are incorporated herein byreference.

FIELD

The present disclosure relates to a cooling system, such as for coolingelectronic equipment mounted to a rack.

BACKGROUND

This section provides This section provides background informationrelated to the present disclosure, which is not necessarily prior art.

A rack server, also called a rack mounted server, is a computer designedto be installed in a framework called a server rack. The rack containsmultiple mounting slots called bays, each designed to hold heatproducing electronic equipment, such as computer hardware (rack serversand other similar hardware systems, for example), telecommunicationsequipment, power equipment (protection, conditioner, transformers),industrial automation equipment, etc. The electronic equipment issecured in place with screws, rails, or other similar securing systems.The securing systems permit the electronic equipment to be quicklyinserted and removed from the server rack. For example, rack servers andother similar hardware systems that are placed within the server rackare designed in a standardized manner, such that hardware provided fromone company can be mounted in the same space as hardware from anothercompany. Rack sizes are allocated as “rack units” or “U” units.Computing hardware is designed in multiples of this unit, such as 1 U, 2U, 4 U, 8 U, or other similar multiples of the rack unit forinstallation in the server racks.

To cool the servers and other electronic equipment in the racks,internal cooling mechanisms, such as fans, integrated within mostequipment draw cold air from the front side of the equipment and exhausthot air out the back side of the equipment. To supply the cold air, datacenters and companies employing server racks, for example, may maintainair conditioners that supply the server rooms with cold air to cool thecomputing components. However, these air conditioning systems typicallycool inefficiently due to various factors (such as room layout,arrangement of the systems to cool the entire room, etc.) and are notdesigned for the specific number of computing systems being employed inthe data center.

The present teachings include cooling systems for cooling heat producingelectronic equipment, such as computer hardware (rack servers and othersimilar hardware systems, for example), telecommunications equipment,power equipment (protection, conditioner, transformers), industrialautomation equipment, etc., that are more efficient, more compact, andmore portable as compared to current cooling systems. The coolingsystems according to the present teachings provide numerous additionaladvantages as described herein, and as one skilled in the art willrecognize.

SUMMARY

This section p This section provides a general summary of thedisclosure, and is not a comprehensive disclosure of its full scope orall of its features.

A closed loop cooling system for electronic equipment. The systemincludes a cabinet having a top panel, walls, and a door defining anenclosure. A rack is within the enclosure, and the electronic equipmentis mounted thereto. An evaporator is within the enclosure below theelectronic equipment. Recirculated cabinet airflow warmed by theelectronic equipment is directed to the evaporator, cooled by theevaporator, and directed back to the electronic equipment to cool theelectronic equipment. A condenser is in fluid communication with theevaporator to circulate coolant therebetween. Ambient airflow fromoutside the cabinet flows across the condenser to cool coolant flowingtherethrough. The recirculated cabinet airflow is maintained independentof the ambient airflow, thereby preventing introduction of added heat orcontaminates into the recirculated cabinet airflow, and not affectingair pressure of the ambient airflow.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings The drawings described herein are for illustrative purposesonly of select embodiments and not all possible implementations, and arenot intended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of a cooling system according to thepresent teachings configured to cool electronic components mounted to arack and enclosed within a cabinet;

FIG. 2 is a perspective view of a cooling system according to thepresent teachings with a condenser unit arranged inside the cabinet,instead of on top of the cabinet as illustrated in FIG. 1;

FIG. 3 is a side view of the cooling system of FIG. 1, but with thecondenser inside the cabinet;

FIG. 4 is a side view of a cooling system that is similar to FIG. 3, butwith a thermosiphon condenser arranged horizontally and without a fan(the thermosiphon condenser is arranged vertically and adjacent a fan inFIG. 3), and with a thermosiphon evaporator at airflow outlets of theelectronic components (the thermosiphon evaporator is adjacent a primaryevaporator in FIG. 3);

FIG. 5A is a front perspective view of an evaporator unit according tothe present teachings;

FIG. 5B is a rear perspective view of the evaporator unit of FIG. 5B;

FIG. 6 is a front perspective view of a condenser unit in accordancewith the present teachings;

FIG. 7 illustrates the cooling system according to the present teachingsconfigured to cool electronic components mounted to an open rack;

FIG. 8 illustrates the cooling system of FIG. 7 arranged between twoadjacent racks to cool electronic components of the adjacent racks;

FIG. 9A illustrates a first evaporator unit coupled to a firstevaporator blower unit, the first evaporator unit having a first coolingcapacity and the first evaporator blower unit having a first airflowgeneration capacity;

FIG. 9B illustrates a second evaporator unit coupled to the firstevaporator blower unit, the second evaporator unit having a secondcooling capacity that is less than the first cooling capacity;

FIG. 9C illustrates a third evaporator unit coupled to the firstevaporator blower unit, the third evaporator unit having a third coolingcapacity that is greater than the first cooling capacity;

FIG. 9D illustrates the first evaporator unit coupled to a secondevaporator blower unit having a second airflow generation capacity thatis less than the first airflow generation capacity;

FIG. 9E illustrates the first evaporator unit coupled to a thirdevaporator blower unit having a third airflow generation capacity thatis greater than the first airflow generation capacity;

FIG. 10A illustrates a first condenser unit coupled to a first condenserblower unit, the first condenser unit having a first cooling capacityand the first condenser blower unit having a first airflow generationcapacity;

FIG. 10B illustrates a second condenser unit coupled to the firstcondenser blower unit, the second condenser unit having a second coolingcapacity that is less than the first cooling capacity;

FIG. 10C illustrates a third condenser unit coupled to the firstcondenser blower unit, the third condenser unit having a third coolingcapacity that is greater than the first cooling capacity;

FIG. 10D illustrates the first condenser unit coupled to a secondcondenser blower unit having a second airflow generation capacity thatis lower than the first airflow generation capacity; and

FIG. 10E illustrates the first condenser unit coupled to a thirdcondenser blower unit having a third airflow generation capacity that isgreater than the first airflow generation capacity.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

With initial reference to FIG. 1, a cooling system according to thepresent teachings is generally illustrated at reference numeral 10. Thecooling system 10 generally includes an evaporator unit or module 12 anda condenser unit or module 14. A conduit 16 including refrigerant lines(such as lines 140, 142 illustrated in FIGS. 3 and 4) connects theevaporator unit 12 and the condenser unit 14. The cooling system 10 isconfigured to cool any suitable type of electronic equipment 18, such asany suitable computing hardware including rack servers as illustrated inthe exemplary drawings. The electronic equipment 18 can be mounted to arack 20, such as a server rack, as explained herein.

In the example of FIG. 1, the electronic equipment 18, the rack 20, andthe evaporator unit 12 are housed within a cabinet 30 seated on a floor32. The cabinet 30 generally includes a base 40, a top 42, a pair ofsidewalls 44, a rear door 46, and a front door 48. The base 40 can be anopen or closed base, and is typically seated on floor 32 of a serverroom, or any other suitable room. The top 42 of the cabinet 30 caninclude one or more openings 50 through which power cables andinformation technology cables can be routed to the electronic equipment18. One or more of the sidewalls 44, the rear door 46, and the frontdoor 48 may include cooling vents.

The server rack 20 includes a plurality of posts, such as posts 22A and22B, to which the electronic equipment 18 is mounted. The electronicequipment 18 can be mounted above the evaporator unit 12, whichadvantageously reduces the possibility that any liquid leaked from theevaporator unit 12 will reach the electronic equipment 18. Theevaporator unit 12 may be mounted to the rack 20 at a position on therack 20 below the electronic equipment 18. The evaporator unit 12 mayalso be mounted to a rack separate from the rack 20, mounted to the base40, or arranged in any other suitable manner. For example, in someapplications the evaporator unit 12 may be mounted above the electronicequipment 18. In other applications the evaporator unit 12 may bemounted to an intermediate position on the rack 20 such that electronicequipment 18 is both above and below the evaporator unit 12.

The evaporator unit 12 is advantageously positioned beneath theelectronic equipment 18 and directly adjacent thereto so that cool airflowing from the evaporator unit 12 has a short distance to travel toreach the electronic equipment 18, and particularly a front end 18A ofthe electronic equipment 18, where the cooled air can be drawn into andthrough the electronic equipment 18 by fans (see FIGS. 3 and 5 at 122)or any other suitable air circulation device. An upper outlet 120 of theevaporator unit 12 is advantageously arranged just beneath the frontends 18A of the electronic equipment 18 so that cool air blowing throughthe upper outlet 120 has a short distance to travel in order to reachthe front ends 18A of the electronic equipment 18. The upper outlet 120can slightly protrude out beyond the front ends 18A, and in someinstances beyond front posts 22A and 22B as illustrated in FIG. 7 forexample, to facilitate airflow to the front ends 18A.

Extending from the condenser unit 14 is an outlet tube 60 and an inlettube 62. In the example illustrated, the outlet tube 60 extends to anoutlet aperture 64 defined in ceiling 70, and the inlet tube 62 extendsto an inlet aperture 66 defined in the ceiling 70. A deflector 72 can bearranged over the outlet aperture 64 as illustrated to direct airflowexiting the condenser unit 14 away from airflow entering the condenserunit 14. Although the example of FIG. 1 illustrates the outlet and inlettubes 60 and 62 extending to the ceiling 70, the outlet and inlet tubes60 and 62 can extend to any other suitable location. For example, theoutlet and inlet tubes 60 and 62 can extend to a wall, ventilationmanifold, roof, etc.

The cooling system 10 may optionally include a thermosiphon system 80.The thermosiphon system 80 generally includes a thermosiphon condenserunit 82 and a thermosiphon evaporator unit 84, which are connected by athermosiphon conduit 86. In the example illustrated the thermosiphoncondenser unit 82 is arranged above the ceiling 70 proximate to theinlet aperture 66. However, the thermosiphon condenser unit 82 can bearranged at any suitable position, such as where relatively cool airflowcan pass through the thermosiphon condenser unit 82 in order to coolcoolant flowing therethrough, which has been warmed by heat generated bythe electronic equipment 18, as explained in detail herein. Thethermosiphon condenser unit 82 can be positioned in any environment thatis cooler than the rack 20 and elevated above the thermosiphonevaporator unit 84, such as above the ceiling 70, in an adjacent room,in an adjacent building, etc. Although the thermosiphon evaporator unit84 is illustrated in FIG. 1 as adjacent to the evaporator unit 12, thethermosiphon evaporator unit 84 can be arranged at any other suitableposition to cool air that has been warmed by the electronic equipment 18as explained herein.

With reference to FIG. 2, the condenser unit 14 can be arranged withinthe cabinet 30, such as above the electronic equipment 18, which canadvantageously reduce the height of the cooling system 10 and make thecooling system 10 portable. The condenser unit 14 can be mounted to therack 20, or to any other suitable mounting rack or device. The condenserunit 14 can also be mounted at any other suitable location, such as tothe ceiling 70, a building roof, a building wall, seated on the floor 32at another location within the room, arranged in another room, etc. Theevaporator unit 12 and the condenser unit 14 may be arranged so thatthey overlap, which can advantageously reduce the size of the coolingsystem 10.

With continued reference to FIGS. 1 and 2, and additional reference toFIG. 3, additional features of the cooling system 10 will now bedescribed, as well as operation of the cooling system 10. The evaporatorunit 12 includes an evaporator 110, a blower 112, a control module 114,a return air inlet 116, and the upper outlet 120 (cold air supply). Thecondenser unit 14 includes a compressor 130, condenser 132, and a blower134.

Extending between the condenser 132 and the evaporator 110 is a firstrefrigerant conduit or tube 140. Extending between the evaporator 110and the compressor 130 is a second conduit or tube 142. The compressor130 and the condenser 132 are also connected by a suitable refrigerantconduit or tube. Arranged along the first tube 140 between the condenser132 and the evaporator 110 is any suitable thermal expansion device 144,such as a thermal expansion valve (TXV), electronic expansion valve(EXV), orifice tube, or capillary tube. The thermal expansion device 144may be arranged in the evaporator module 12, the condenser module 14, orat any location therebetween.

During operation of the cooling system 10, refrigerant is pumped by thecompressor 130. Refrigerant enters the thermal expansion device 144 as arelatively warm, high pressure liquid. At the thermal expansion device144, the high pressure liquid expands, which reduces the pressure of therefrigerant. The now low pressure liquid refrigerant passes through thefirst tube 140 to the evaporator 110. As the low pressure liquidrefrigerant flows through the evaporator 110, the refrigerant absorbsheat of airflow warmed by the electronic equipment 18, which is drawninto the return air inlet 116 and across the evaporator 110 by theblower 112. The evaporator 110 can have a generally linear shape, or anyother suitable shape, such as a V-shape or U-shape to increase thesurface area thereof, and the capacity of the evaporator 110 to absorbheat into the refrigerant.

The air cooled at the evaporator 110 is blown out from within theevaporator unit 12 through the upper outlet 120 by the blower 112 to thefront 18A of the electronic equipment 18 in order to cool the electronicequipment 18. As described further herein, the blower 112 may also blowcooled air out through side outlets 180 and 182 (see FIGS. 5A and 5B forexample) of the evaporator unit 12 in order to direct cooled air toadjacent racks of electronic equipment (see FIG. 8, for example, and theadditional description provided herein). The cooled air can be drawnthrough the electronic equipment 18 by fans 122 thereof in order to coolthe electronic equipment 18. As air flows through the electronicequipment 18 and cools the electronic equipment 18, the air is warmed bythe electronic equipment 18 and can be pushed out from within theelectronic equipment 18 by the fans 122. The warmed air is then drawnback into the evaporator unit 12 and across the evaporator 110 by theblower 112 in order to again cool the air as the airflow cycle repeats.The fans 122 are optional and may not be included with all electronicequipment 18. The airflow of the evaporator unit 12 can force airflowthrough the electronic equipment 18 to provide passive cooling, thusmaking the fans 122 unnecessary and conserving energy.

As the refrigerant of the evaporator 110 absorbs heat, the refrigerantis converted to a low pressure gas, and flows from the evaporator 110 tothe compressor 130 through the second tube 142. The compressor 130compresses the low pressure gas, and thus pressurizes the low pressuregas refrigerant into a high pressure gas refrigerant. The high pressuregas refrigerant is pumped to the condenser 132 by the compressor 130. Atthe condenser 132, heat is radiated out of the refrigerant, and therefrigerant is converted back into a high pressure liquid prior to beingpumped back to the thermal expansion device 144. The blower 134 drawsair into the condenser unit 14 through the inlet tube 62, and across thecondenser 132. The heat radiated from the condenser 132 is blown outfrom within the condenser unit 14 by the blower 134 through the outlettube 60.

The cooling system 10 can advantageously include the thermosiphon system80, which can advantageously cool airflow warmed by the electronicequipment 18 without operating the compressor 130, which saves energy.The thermosiphon system 80 is particularly useful in coolerenvironments. The thermosiphon system 80 includes a thermosiphoncondenser 150 arranged within the thermosiphon condenser unit 82. Tofacilitate circulation of air across the thermosiphon condenser 150, thethermosiphon condenser unit 82 may include a fan 152. The thermosiphonconduit 86 extends from the thermosiphon condenser 150 to thethermosiphon evaporator unit 84, and specifically a thermosiphonevaporator 154 thereof. Extending through the thermosiphon conduit 86 isa first conduit or tube 160 and a second conduit or tube 162. The firstand second tubes 160 and 162 can be any suitable tubes sufficient tocarry any suitable coolant, such as water, refrigerant, etc., betweenthe thermosiphon condenser 150 and the thermosiphon evaporator 154.

In the example of FIG. 3, the thermosiphon evaporator unit 84 and thethermosiphon evaporator 154 thereof are arranged adjacent to theevaporator unit 12 (and in some applications the evaporators 110 and 154may be arranged such that they abut, or generally abut, one another).However, the thermosiphon evaporator unit 84 can be arranged at anyother suitable position, such as at the rear 18B of the electronicequipment 18, as illustrated in FIG. 4 for example. Although thethermosiphon condenser 150 is illustrated as extending vertically inFIG. 3, the thermosiphon condenser 150 can be horizontally arranged asillustrated in FIG. 4. By arranging the thermosiphon condenser 150horizontally and across the inlet tube 62 as illustrated in FIG. 4, theblower 134 will advantageously draw air across the thermosiphoncondenser 150, which in many instances will make it possible toeliminate the fan 152 and conserve energy.

At the thermosiphon condenser 150, airflow passing across the condenser150 will cool coolant passing through the condenser 150. The cooledcoolant flows from the thermosiphon condenser 150 through the first tube160 down to the thermosiphon evaporator 154. Gravity draws the coolantto the evaporator 154 from the condenser 150, thus advantageouslyeliminating the need for a compressor or other pump. At the thermosiphonevaporator 154, the cool coolant cools warm airflow passing across thethermosiphon evaporator 154, the warmed airflow having been warmed bythe electronic equipment 18. The coolant is warmed by the warm airflowpassing across the evaporator 154. As the coolant is warmed, the coolantbecomes less dense and more buoyant, which causes the warmed coolant torise up through the second tube 162 to the thermosiphon condenser 150,where the warmed coolant is cooled. After the coolant has cooled, thecoolant flows back to the evaporator 154 to again cool airflow passingacross the evaporator 154. The thermosiphon system 80 can include ashutoff valve 164, such as along the first tube 160, for stoppingcoolant flow when the thermosiphon system 80 is not in use. Thethermosiphon system 80 can be used in conjunction with operation of thecompressor 130, or in place of operation of the compressor 130, such asduring cooler conditions.

With additional reference to FIGS. 5A and 5B, the evaporator unit 12will now be described in additional detail. The evaporator unit 12includes a top 170, a bottom 172, a front end 174, and a rear end 176.The evaporator unit 12 further includes a first side 178A and a secondside 178B. The upper outlet (cold air supply) 120 is at the top 170proximate to the front end 174. A first side outlet 180 can be arrangedat the first side 178A proximate to the front end 174, and a second sideoutlet 182 can be arranged at the second side 178B proximate to thefront end 174. As illustrated in FIG. 8, the first and second sideoutlets 180 and 182 can advantageously be used to direct cooled airflowto first and second adjacent server racks 310A and 310B in order to coolelectronic equipment 312A and 312B thereof. A lower outlet (cold supplyoutlet) can be arranged at the bottom 172 proximate to the front end174. The lower outlet 184 can be used in applications where electronicequipment to be cooled is arranged below the evaporator unit 12. Thefirst side outlet 180, the second side outlet 182, and the lower outlet184 can be selectively covered by covers 190, 192, and 194 respectivelywhen not in use. The return air inlet 116 is arranged at the rear end176 as illustrated, but may be arranged at any other suitable position,such as on the top 170 and/or the sides 178A/178B.

The control module 114 can be arranged at any suitable position aboutthe evaporator unit 12, or remote to the evaporator unit 12. The controlmodule 114 is configured to control operation of the evaporator unit 12,the condenser unit 14, and/or the compressor 130, such as to control thetemperature of the cooling system 10. The control module 114 can furthercontrol opening and closing of the shutoff valve 164 to controlactivation of the thermosiphon system 80. Further, the control module114 may provide status information to an end user, including whether theunit rack mount cooling system is on or off, the temperature settingsfor the cooling system, or any other similar information. In thisapplication, the term “module” may be replaced with the term “circuit.”The term “module” may refer to, be part of, or include processorhardware (shared, dedicated, or group) that executes code and memoryhardware (shared, dedicated, or group) that stores code executed by theprocessor hardware. The code is configured to provide the features ofthe control module 114.

The evaporator unit 12 can be mounted using any suitable mountinghardware, such as brackets or mounts 210, 212, 214, and 216. Thebrackets 210 and 212 are arranged at first and second sides 178A and1788 respectively, and towards the front end 174. The brackets 214 and216 are arranged at the sides 178A and 1788 respectively, and generallytowards the rear end 176. One or more of the mounts 210, 212, 214, and216 can be used to mount the evaporator unit 12 to the rack 20, anyother suitable rack, to the base 40 of the cabinet 30, or in any othersuitable manner below the electronic equipment 18.

With reference to FIG. 6, the condenser unit 14 includes a top 250, abottom 252, a front 254, a rear 256, and first and second sides 258A and258B. At the top 250 is an air outlet 260, to which the outlet tube 60is connected, and through which the blower 134 blows air out from withinthe condenser unit 14. Also at the top 250 is an air inlet 262, throughwhich the blower 134 draws air into the condenser unit 14. The inlettube 62 is arranged against the air inlet 262. To facilitate arrangementof the outlet tube 60 at the air outlet 260, an air outlet flange 264can be arranged over the air outlet 260. Similarly air inlet flanges 266can be arrange over the air inlet 262 to facilitate arrangement of theinlet tube 62 over the air inlet 262. Two air inlet flanges 266 areillustrated and can be used when two inlet tubes 62 are provided. Whenonly a single inlet tube 62 is used, only a single air inlet flange 266is used (see FIGS. 1, 2, and 8). Although the outlet 260 and the inlets262 are illustrated as arranged on the top 250, they may be arranged atany other suitable position, such as on the sides 258A/258B, at thefront 254, or at the rear 256.

The condenser unit 14 includes any suitable mounting hardware, such asbrackets or mounts 270, 272, 274, and 276. The brackets 270 and 272 areat the first and second sides 258A and 258B respectively, and proximateto the front 254. Brackets 274 and 276 are at the first and second sides258A and 258B respectively, proximate to the rear 256. The brackets 270,272, 274, and 276 can be used to mount the condenser unit 14 to the rack20 above the electronic equipment 18, or to any other suitable mountinghardware. One or more of the brackets 270, 272, 274, and 276 can berearranged, such as moved to the bottom 252, in order to facilitatemounting the condenser unit 14 to the top 42 of the cabinet 30, asillustrated in FIG. 1, for example. With reference to FIG. 2, thebrackets 270, 272, 274, and 276 can be used to mount the condenser unitwithin the cabinet 30. The brackets 270, 272, 274, and 276 can also beused to mount the condenser unit to an open rack installation, such asinside the open rack or on top of the open rack, as illustrated in FIG.7.

FIG. 7 illustrates an open rack installation including a plurality ofposts, such as first post 22A, second post 22B, third post 22C, and afourth post that is not visible. The installation of FIG. 7 includes abase 24 and a top 26. As illustrated in FIG. 7, the electronic equipment18 can be mounted directly to at least the front first and second posts22A and 22B. The evaporator unit 12 can be mounted directly to the frontfirst and second posts 22A and 22B with the brackets 210 and 212. Theevaporator unit 12 may also be mounted to the third post 22C and thefourth post with brackets 214 and 216. Although the condenser unit 14 isillustrated as mounted on the top 26, the condenser unit 14 can bemounted beneath the top 26 in any suitable manner, such as to the posts22A, 22B, 22C (and the hidden fourth post) with one or more of thebrackets 270, 272, 274, and 276.

FIG. 8 illustrates the cooling system 10 in an open rack installationbetween a first adjacent server rack 310A and a second adjacent serverrack 310B including electronic equipment 312A and 312B respectively. Thefirst and second side outlets 180 and 182 are uncovered, which allowscooled airflow to exit therefrom and cool the electronic equipment 312Aand 312B. Warm airflow exiting the electronic equipment 312A and 312B atthe rear ends thereof is drawn into the evaporator unit 12 by the blower112, for cooling by the evaporator unit 12 (and or the thermosiphonevaporator 154) and recirculated to the electronic equipment 312A and312B. Although the condenser unit 14 is illustrated as mounted to thetop of the open rack installation, the condenser unit 14 may be mountedbeneath the top to one or more of the posts 22A, 22B, 22C, and thefourth hidden post, or in any other suitable manner. The condenser unit14 may also be arranged remote to the open rack installation, asexplained above. Although FIG. 8 illustrates open rack installations,cabinet installations may also be used with sidewalls removed. Forexample, the cooling system 10 can be arranged within the cabinet 30 andthe sidewalls 44 thereof can be removed to allow airflow to travel tothe first and second adjacent server racks 310A and 310B. The first andsecond adjacent server racks 310A and 310B can be housed within cabinetssimilar to the cabinet 30, but with at least the sidewalls abutting thecooling system 10 removed.

The present teachings thus advantageously provide for a cooling system10 with increased cooling efficiency, simplicity, and portability. Thecooling system 10 also advantageously requires less floor space ascompared to existing cooling systems. Because the evaporator unit 12 isconnected to the rack 20, or adjacent thereto, the distance that coldair blown from the evaporator unit 12 must travel to reach theelectronic equipment 18 and return to the evaporator unit 12 from theelectronic equipment 18, is greatly reduced as compared to currentcooling systems, which increases efficiency and enhances the ability ofthe cooling system 10 to cool the electronic equipment 18. By reducingthe distance that the air travels to and from the evaporator unit 12,there is less of a chance that warmer air outside of the rack 20 willmix with the cool air exiting the evaporator unit 12, which reduces thecooling efficiency of the cooling system 10. The cooling system 10 isalso more efficient as compared to existing systems because theevaporator unit 12 only directs cooled air to the front ends 18A of theelectronic equipment 18, which is where the electronic equipment 18typically draws air in. Existing systems often disperse cooled air aboutan entire server room, which is greatly inefficient.

The present teachings provide numerous additional advantages,particularly advantages associated with separating the evaporator unit12 and the condenser unit 14. For example, the evaporator unit 12 can bearranged so that it is not above the electronic equipment 18, whichprotects against any possibility of water leaking on the electronicequipment 18. Also, separating the evaporator and condenser units 12 and14 overcomes various issues that arise from arranging both theevaporator and condenser units 12 and 14 at the bottom of the rack 20.When the evaporator and condenser units 12 and 14 are arranged togetherat the bottom of the rack 20, as is the case in some packaged ACsystems, a standard rear door 46 that is perforated or solid cannot beused. Instead, the rear door 46 must be modified and customized toaccommodate ducting leading away from the cabinet 30, such as byshortening the rear door 46, which can increase costs. Such ducting caninhibit access to components within the cabinet 30 and undesirablyincrease the expense of the assembly. The present teachingsadvantageously eliminate the need for such ducting, which advantageouslysimplifies assembly and installation, and reduces the cost of thecooling system 10.

As illustrated in FIG. 2, for example, the cabinet 30 includes a top 42,which advantageously defines an air outlet 260 and an air inlet 262. Theair inlet 262 is connected directly to (or by way of any suitableconduit) the condenser unit 14. Ambient air from outside the cabinet 30is drawn into the condenser unit 14 and to the condenser 132 through theair inlet 262, such as by the blower 134. The ambient air absorbs heatreleased by the electronic equipment 18. Air is exhausted out of thecabinet 30 through the air outlet 260. Advantageously, the air inlet 262directs air into the cabinet 30 to create an independent airflow of thecondenser unit's ambient air that exits through the air outlet 260 toprevent it from mixing with air inside the cabinet 30. Alternatively thecondenser unit 14 can be mounted on top of the cabinet 30 (see FIG. 1,for example) to maintain the independent airflows of the condenser unit14 and evaporator unit 12, and not introduce ambient air into thecabinet 30 where the electronic equipment 18 is. The condenser unit 14may be mounted at any other suitable position exterior to the cabinet 30as well. For example, the condenser unit 14 may be mounted in a window,on a floor, in another room, in another building, etc.

The cooling system 10 is advantageously a closed loop cooling systemthat provides separate airflows across the evaporator unit/module 12 andthe condenser unit/module 14. Throughout the drawings, arrowsrepresenting ambient airflow that flows across the condenser unit 14 areshaded, while arrows representing airflow recirculated within thecabinet 30 to cool the electronic equipment 18 are not shaded. There isno mixing of the recirculated air within the cabinet 30 with ambient airoutside of the cabinet 30. Thus, air pressure within the cabinet 30remains neutral. As a result of the two independent airflows, thecooling system 10 has no effect on the room or building's air pressuresystem. Without the airflows being independent, the cooling system 10could adversely affect the air pressure within the space. For example,cooling systems without independent airflows can create a negative airpressure within the room or building, which starves the condenser 132 ofair and makes opening doors very difficult. Furthermore, the efficiencyof the cooling system may decrease as the condenser 132 partially takesconditioned air from the evaporator 110 to absorb the heat, instead ofthe conditioned air exclusively cooling the electronics 18. Thecondenser unit 14 advantageously prevents warm and potentiallycontaminated, ambient air from adding to the heat load within thecabinet 30. Furthermore, the independent airflows of the evaporator 110and the condenser 132 allows cooling of the electronic equipment 18inside the cabinet 30 without having to cool the general area around thecabinet 30, which additionally increases the cooling efficiency of thecooling system 10.

Independent airflows are critical in positively pressurized rooms orbuildings. For example, clean rooms keep their space positivelypressurized to prevent contaminates from entering the conditioned roomthrough doors when occupants enter or leave. However, an air conditionerneeds to exhaust the warm condenser air out of the space, or it willheat up the clean room. Therefore, having independent airflows withinthe pressurized room is imperative. Not having independent airflows in apressurized room could force air through the air conditioner and out theclean room via the condenser exhaust. As a result, the room may nolonger stay positively pressurized, and the clean room may becomecontaminated. Furthermore the condenser motor may not be powerful enoughto overcome the pressurized room to properly exhaust the warm air out ofthe room. The independent airflows provided by the present disclosureadvantageously overcome these issues.

The cooling system 10 is advantageously portable, particularly when thecondenser unit 14 is mounted inside or on top of cabinet 30. Forexample, arranging the condenser unit 14 inside of the cabinet 30 allowsthe cabinet 30 to be easily moved from room to room, and building tobuilding. The cooling system 10 is also portable when the condenser unit14 is placed elsewhere, such as in a window, on a floor near the cabinet30, in a ceiling, or at any suitable position spaced apart from thecabinet 30. The cooling system 10 provides a turnkey cooling solution,with a micro data center inside the cabinet 30. The cooling system 10 issuitable for disaster relief applications. For example, in the case of anatural disaster the cooling system 10 with the data center therein maybe moved quickly and efficiently to a new location. The cooling system10 is also well suited for users leasing space because the coolingsystem 10 may be easily moved to a new location once the lease expires.The cooling system 10 is not a lease-hold improvement, but can rather beeasily moved to a new space.

As illustrated in FIG. 3, for example, outlet tube 60 extending from theair outlet 260 provides simplified delivery of exhaust air up into thedrop ceiling 70. The exhaust and return ducting (e.g., outlet tube 60and inlet tube 62) do not interfere with one's ability to service theelectronic equipment 18. Return air ducting, such as by way of inlettube 62, advantageously delivers air to the condenser unit 14 tomaintain neutral air pressure inside the room (small closet) where thecooling system 10 is located. This advantageously prevents negativepressure from being created in the room, such as in cases where onlyexhaust air is ducted into the ceiling 70. The cooling system 10 mayinclude any suitable standard server rack 20, with little or nomodifications being made thereto.

Little or no sound emanates from the cooling system 10 to thesurrounding environment. This is because, for example, the entirecooling system (e.g., compressor 130, blower 112, blower 134, etc.) canbe advantageously located inside of the cabinet 30, which may be madesoundproof. Thus the cooling system 10 is well suited for office spaces,video production studios, etc. Because the cooling system 10 is aself-contained system, it is well suited for use in industrialenvironments as well, such as corrosive environments.

With reference to FIGS. 9A-10E for example, the evaporator unit ormodule 12 and the condenser unit or module 14 may each be configured asmodular systems. Air conditioners typically have model specific designs,meaning that each model is designed to work at one cooling capacity. Ifthe heat load that is being cooled increases and no longer can be cooledadequately with the existing air conditioner, then a new larger airconditioner needs to replace the existing air conditioner. Replacing asmaller air conditioner with a larger air conditioner is expensive,disruptive, and wasteful. For example, as a company grows larger theexpansion of an IT network that is housed in server racks is verycommon. Companies have few cooling options to satisfy the growingcooling demand of their IT network, such as the following: (1) installan air conditioning system that is too large for their current ITnetwork; (2) add supplemental cooling when the heat load of the ITnetwork is too large for the current air conditioner; or (3) replace thecurrent air conditioner when it can no longer keep up with the heatload.

With respect to installing an oversized cooler for the IT network, thisrequires a large capital investment, and may result in overspending on acooling system. Also, oversized coolers can be inefficient (single speedcompressor). With respect to the supplemental cooling, it can beimpossible to supplement the cooling in a single rack application. Twosmaller coolers are less efficient than one larger cooler. With respectto replacing the undersized cooler, it is typically expensive topurchase a new cooler before the end of its life. It can also bedisruptive to the IT network when removing the existing cooler, andinstalling a new cooler.

The present disclosure advantageously provides a modular split systemcooler (rackmount or otherwise), which can be easily modified to managechanges in heat load over time. For example and as illustrated in FIG.9A, an evaporator module 12A having a first cooling capacity isillustrated. The evaporator module 12A generally includes an evaporator110A having a first cooling capacity, the evaporator 110A includingevaporator coils. Also included are refrigerant connections extendingfrom the evaporator 110A, and any suitable thermal expansion device 124A(evaporator modules 12B and 12C include thermal expansion devices 124Band 124C respectively). The thermal expansion device 124A (as well asthe thermal expansion devices 124B and 124C) is located prior to theevaporator 110A, and modulates the refrigerant flow within the coolingsystem 10. The thermal expansion device 124A receives high pressure andtemperature refrigerant from the condenser 132, and drops the pressureof the refrigerant. The thermal expansion device 124A then delivers thelow pressure refrigerant to the evaporator 110A to absorb the heatproduced by the electronic equipment 18 inside the cabinet 30.

The evaporator module 12A is in cooperation with an evaporator blowermodule 118A having a first airflow generating capacity. The evaporatorblower module 118A includes a blower motor and fan 112A for generatingairflow to the evaporator module 12A. The evaporator blower module 118Amay optionally include a controller 126A configured to operate the motorand fan 112A in a manner most efficient to cool the electronic equipment18. The evaporator blower module 118A and the evaporator module 12A maybe coupled together in any suitable manner, and/or secured to the rack20 adjacent to one another.

In applications where relatively less cooling capacity is required, theevaporator module 12A may be replaced with evaporator module 12B (FIG.9B). The evaporator module 12B is similar to the evaporator module 12A,and thus the elements thereof are illustrated with the same referencenumerals, but with the suffix “B.” The evaporator module 12B has a lowercooling capacity as compared to the evaporator module 12A. For example,the evaporator 110B may be smaller than the evaporator 110A.

In applications where additional cooling capacity is required, anevaporator module 12C may be used (see FIG. 9C). The evaporator module12C has a larger cooling capacity than both the evaporator module 12Aand the evaporator module 12B. The features of the evaporator module 12Care similar to the evaporator modules 12A and 12B, and thus the featuresare illustrated with the same reference numerals, but with the suffix“C.” The evaporator 110C has a higher cooling capacity than each one ofthe evaporators 110A and 110B. The evaporator module 12C can be coupledto the evaporator blower module 118A in any suitable manner, and/ormounted to the rack 20 adjacent to the evaporator blower module 118A.

With reference to FIG. 9D, the evaporator module 12A may be coupled to,or mounted to the rack 20 adjacent to, an evaporator blower module 118Bhaving an airflow generating capacity that is lower than the evaporatorblower module 118A. This reduced airflow generating capacity may be dueto a smaller motor and/or fan 112B. With reference to FIG. 9E, anevaporator blower module 118C having a greater airflow generatingcapacity than each one of the blower modules 118A and 118B may becoupled to the evaporator module 12A, or mounted to the rack 20 adjacentto the evaporator module 12A. The evaporator blower module 118Cgenerates relatively greater airflow in any suitable manner, such as byhaving a motor and fan 112C that is larger than that of the evaporatorblower modules 118A and 118B. Although FIG. 9D illustrates theevaporator blower module 118B as associated with the evaporator module12A, the evaporator blower module 118B may be associated with theevaporator module 12B or 12C depending on the amount of airflow that isoptimal for the application. Likewise, although the evaporator blowermodule 118C is illustrated in FIG. 9E as associated with the evaporatormodule 12A, the evaporator blower module 118C may be associated witheither one of the evaporator module 12B or 12C depending on the amountof airflow required.

Thus the cooling system 10 may be customized with an evaporator module12A, 12B, 12C and evaporator blower module 118A, 118B, 118C combinationthat generates cooling capacity and airflow optimal to satisfy thecooling needs of the particular electronic equipment 18 mounted to therack 20. As the electronic equipment 18 changes (and/or utilizationthereof changes), different evaporator module 12A, 12B, 12C andevaporator blower module 118A, 118B, 118C combinations can be customizedto most efficiently cool the electronic equipment. Any one of theevaporator modules 12A, 12B, 12C may be coupled to any one of theevaporator blower modules 118A, 118B, 118C in any suitable manner, suchas with any suitable coupling devices 128. The coupling devices 128 maybe any suitable mating surfaces, fasteners, coupling members, etc. Anysuitable wire harnesses may be used as well.

With reference to FIGS. 10A, 10B, 10C, 10D, and 10E, the condensermodule 14 may also be selected from a plurality of condenser modules14A, 14B, 14C of different cooling capacities, and associated with anyone of a plurality of condenser blower modules 136A, 136B, 136C havingdifferent airflow generating capacities depending on the cooling and/orairflow needs of the electronic equipment 18. With initial reference toFIG. 10A, the condenser module 14A includes a compressor 130A and acondenser 132A including condenser coils. The compressor 130A and thecondenser 132A have refrigerant connections, and are configured togenerate a first cooling capacity. The condenser module 14A may becoupled to condenser blower module 136A in any suitable manner, ormounted adjacent thereto on the rack 20. The condenser blower module136A has a motor and fan 134A configured to provide a first airflowgenerating capacity.

With reference to FIG. 10B, condenser module 14B includes a compressor130B and a condenser 132B that provide a cooling capacity less than thatprovided by the compressor 130A and the condenser 132A. For example, thecompressor 130B may be smaller than the compressor 130A, and thecondenser 132B may be smaller than the condenser 132A. With reference toFIG. 10C, the condenser module 14C may be coupled to the condenserblower module 136A, or mounted to the rack 20 adjacent to the condenserblower module 136A. The condenser module 14C has a cooling capacity thatis greater than the cooling capacity of each one of the condenser module14A and the condenser module 14B. The condenser module 14C includes acompressor 130C and a condenser 132C.

FIG. 10D illustrates another condenser blower module in accordance withthe present disclosure at reference numeral 136B. The condenser blowermodule 136B includes a motor and fan 134B. The condenser blower module136B has an airflow generating capacity that is less than the condenserblower module 136A, such as because the motor and fan 134B is smallerthan the motor and fan 112A. With reference to FIG. 10E, the presentdisclosure includes an additional condenser blower module 136C having anairflow generating capacity that is greater than each one of thecondenser blower modules 136A and 136B, such as because motor and fan134C is larger than each one of the motor and fan 134A and 134B.

Although the condenser blower module 136B is illustrated in FIG. 10D asassociated with the condenser module 14A, the condenser blower module136B may be coupled to, or mounted to the rack 20 adjacent to, thecondenser module 14B or 14C. Similarly, although FIG. 10E illustratesthe condenser blower module 136C as associated with the condenser module14A, the condenser blower module 136C may be coupled to, or mounted tothe rack 20 adjacent to, the condenser module 14B or 14C. Thus thecooling system 10 may include any combination of the condenser modules14A, 14B, 14C and condenser blower modules 136A, 136B, 136C to provideoptimal cooling capacity and airflow for cooling the electronicequipment 18 in the most efficient manner. Any one of the condensermodules 14A, 14B, 14C may be coupled to any one of the condenser blowermodules 136A, 136B, 136C in any suitable manner, such as with anysuitable coupling devices 138. The coupling devices 138 may be anysuitable mating surfaces, fasteners, coupling members, etc. Any suitablewire harnesses may be used as well.

This modularity advantageously allows cooling capacity and airflowcapacity to be modified at a relatively low cost as compared toreplacing an entire cooling system with a larger capacity cooling systemas cooling needs change. Furthermore, the modularity of the presentdisclosure results in reduced disruption to the electronic equipment 18as compared to a full cooling system replacement. Still further, themodularity of the present disclosure avoids the installation of anoversized cooler when it is not necessary, which requires a high initialcapital investment. Also, an oversized cooler may be less efficient thana properly sized cooler. Another advantage of the modularity of thepresent disclosure is that an end user may store various evaporatormodules 12A, 12B, 12C, various evaporator blower modules 118A, 118B,118C, various condenser modules 14A, 14B, 14C, and various condenserblower modules 136A, 136B, 136C on hand for use in the event of apossible equipment failure. The modularity of the present disclosure mayalso lead to reduced manufacturing costs due to economies of scale ofthe modular design (higher volumes) compared to multiple cooler modelsof different sizes. One skilled it the art will appreciate that thepresent disclosure provides numerous additional advantages as well.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

What is claimed is:
 1. A closed loop cooling system for electronicequipment comprising: a cabinet having a top panel, walls, and a doordefining an enclosure; a rack within the enclosure to which theelectronic equipment is mounted; an evaporator within the enclosurebelow the electronic equipment, recirculated cabinet airflow warmed bythe electronic equipment is directed to the evaporator, cooled by theevaporator, and directed back to the electronic equipment to cool theelectronic equipment; a condenser in fluid communication with theevaporator to circulate coolant therebetween, ambient airflow fromoutside the cabinet flows across the condenser to cool coolant flowingtherethrough; a condenser module defining an inlet and an outlet, thecondenser module including the condenser and a blower, the condensermodule is mounted to the cabinet above the electronic equipment suchthat the evaporator and the condenser are on opposite sides of theelectronic equipment; and an outlet tube extending from the outlet ofthe condenser module and configured to connect to a ceiling of a roomthat the cabinet is in, activation of the blower draws ambient airflowinto the condenser module through the inlet and blows ambient airflowout of the condenser module through the outlet tube to above theceiling; wherein the recirculated cabinet airflow is maintainedindependent of the ambient airflow, thereby preventing introduction ofheat or contaminates into the recirculated cabinet airflow, and notaffecting air pressure of the ambient airflow.
 2. The closed loopcooling system of claim 1, wherein the condenser is inside the cabinetor on top of the cabinet.
 3. The closed loop cooling system of claim 1,wherein the condenser module further includes a compressor.
 4. Theclosed loop cooling system of claim 1, further comprising an evaporatormodule including the evaporator, the evaporator module is in cooperationwith a blower module including a blower; wherein the blower draws airwarmed by the electronic equipment to the evaporator where the warmedair is cooled, and blows the cooled air to the electronic equipment tocool the electronic equipment; and wherein the evaporator module and theblower module are coupled together with any suitable coupling members.5. The closed loop cooling system of claim 4, wherein: the evaporatormodule includes an outlet positioned to direct cooled air exiting theevaporator module to front surfaces of the electronic equipment; and theevaporator module includes a return air inlet positioned to receive airinto the evaporator module that has been warmed by the electronicequipment.
 6. The closed loop cooling system of claim 5, wherein theevaporator module further includes at least one side outlet arranged todirect cooled air exiting the evaporator module to electronic equipmentmounted to one or more secondary racks on either side of the evaporatormodule.
 7. The closed loop cooling system of claim 4, wherein: theevaporator module is one of a plurality of evaporator modules eachhaving different cooling capacities; and each one of the plurality ofevaporator modules includes the evaporator, a metering device, andrefrigerant connections.
 8. The closed loop cooling system of claim 4,wherein the blower module further includes a controller.
 9. The closedloop cooling system of claim 1, further comprising: a blower moduleconfigured to circulate airflow to and from the evaporator, the blowermodule is one of a plurality of blower modules each having differentairflow generating capacities; each one of the plurality of blowermodules includes a motor and a fan; and each one of the plurality ofblower modules is configured to couple with an evaporator moduleincluding the evaporator; wherein the evaporator module and the blowermodule are coupled together with at least one coupling member.
 10. Theclosed loop cooling system of claim 1, wherein: the condenser module isone of a plurality of condenser modules each having different coolingcapacities; each one of the plurality of condenser modules includes thecondenser, a compressor, and refrigerant connections; and each one ofthe plurality of condenser modules is configured to couple with a blowermodule including a motor and a fan with at least one coupling member.11. The closed loop cooling system of claim 10, wherein: the blowermodule is one of a plurality of blower modules each having differentairflow generating capacities; and each one of the plurality of blowermodules is configured to couple with any one of the plurality ofcondenser modules with at least one coupling member.
 12. The closed loopcooling system of claim 1, further comprising an inlet tube extendingfrom the inlet of the condenser module and configured to connect to theceiling, activation of the blower draws ambient airflow into thecondenser module through the inlet tube and the inlet.
 13. A closed loopcooling system for electronic equipment comprising: a cabinet having atop panel, walls, and a door defining an enclosure; a rack within theenclosure to which the electronic equipment is mounted; an evaporatormodule within the enclosure mounted to the rack below the electronicequipment, the evaporator module including an evaporator, a meteringdevice, and evaporator refrigerant connections; an evaporator blowermodule connected to the evaporator module, the evaporator blower moduleincludes a motor and a fan configured to direct recirculated cabinetairflow warmed by the electronic equipment to the evaporator where therecirculated cabinet airflow is cooled, and direct the cooledrecirculated cabinet airflow back to the electronic equipment to coolthe electronic equipment; a condenser module defining an outlet, andincluding a condenser, a compressor, and condenser refrigerantconnections in communication with the evaporator refrigerant connectionsto circulate refrigerant between the condenser and the evaporator, thecondenser module is mounted to the cabinet above the electronicequipment such that the evaporator and the condenser are on oppositesides of the electronic equipment; a condenser blower module connectedto the condenser module, the condenser blower module includes a motorand a fan configured to circulate ambient airflow from outside thecabinet across the condenser to cool refrigerant flowing through thecondenser; and an outlet tube extending from the outlet of the condensermodule and configured to connect to a ceiling of a room that the cabinetis in, activation of the motor and the fan draws ambient airflow intothe condenser module and blows ambient airflow out of the condensermodule through the outlet tube to above the ceiling; wherein therecirculated cabinet airflow is maintained independent of the ambientairflow, thereby preventing introduction of heat or contaminates intothe recirculated cabinet airflow, and not affecting air pressure of theambient airflow.
 14. The closed loop cooling system of claim 13,wherein: the evaporator module is one of a plurality of evaporatormodules each having different cooling capacities; and the evaporatormodule is selected from the plurality of evaporator modules based on thecooling capacity required by the electronic equipment.
 15. The closedloop cooling system of claim 13, wherein: the evaporator blower moduleis one of a plurality of evaporator blower modules each having differentairflow generating capacities; and the evaporator blower module isselected from the plurality of evaporator blower modules based on thecooling capacity required by the electronic equipment.
 16. The closedloop cooling system of claim 13, wherein: the condenser module is one ofa plurality of condenser modules each having different coolingcapacities; and the condenser module is selected from the plurality ofcondenser modules based on the cooling capacity required by theelectronic equipment.
 17. The closed loop cooling system of claim 13,wherein: the condenser blower module is one of a plurality of condenserblower modules each having different airflow generating capacities; andthe condenser blower module is selected from the plurality of condenserblower modules based on the cooling capacity required by the electronicequipment.
 18. The closed loop cooling system of claim 13, furthercomprising an inlet tube extending from an inlet of the condenser moduleand configured to connect to the ceiling, activation of the blower drawsambient airflow into the condenser module through the inlet tube and theinlet.